Catálogo de publicaciones - revistas

<jats:title>Normal skin's curiously abnormal genome</jats:title> <jats:p> Within every tumor, a battle is being waged. As individual tumor cells acquire new mutations that promote their survival and growth, they clonally expand at the expense of tumor cells that are “less fit.” Martincorena <jats:italic>et al.</jats:italic> sequenced 234 biopsies of sun-exposed but physiologically normal skin from four individuals (see the Perspective by Brash). They found a surprisingly high burden of mutations, higher than that of many tumors. Many of the mutations known to drive the growth of cutaneous squamous cell carcinomas were already under strong positive selection. More than a quarter of normal skin cells carried a driver mutation, and every square centimeter of skin contained hundreds of competing mutant clones. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6237" page="880" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aaa6806">880</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6237" page="867" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aac4435">867</jats:related-article> </jats:p>

<jats:title>Stitching C-N bonds from nitro groups</jats:title> <jats:p> Numerous compounds in pharmaceutical research have carbon-nitrogen bonds, and chemists are always looking for ways to make them more efficiently. Gui <jats:italic>et al.</jats:italic> present a method that links the carbon in an olefin to the nitrogen in a nitroaromatic compound (see the Perspective by Kürti). Nitroaromatics are readily available, and the method tolerates a wide range of other chemical groups present on either reacting partner. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6237" page="886" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aab0245">886</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6237" page="863" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aab2812">863</jats:related-article> </jats:p>

<jats:title>Old minerals expose an ancient field</jats:title> <jats:p> Mercury is the only terrestrial planet other than Earth with an active, internally generated magnetic field. Results from the MESSENGER spacecraft indicate that the field is almost as old as the planet. Johnson <jats:italic>et al.</jats:italic> took advantage of close flybys to extract evidence of an ancient magnetic field. Certain minerals are able to “lock in” the signature of a field at the time they crystallize. This remnant magnetization was found in a region on Mercury believed to be 3.8 billion years old. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6237" page="892" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aaa8720">892</jats:related-article> </jats:p>

<jats:title>The difference is found at the margins</jats:title> <jats:p> The terrestrial biosphere absorbs about a quarter of all anthropogenic carbon dioxide emissions, but the amount that they take up varies from year to year. Why? Combining models and observations, Ahlström <jats:italic>et al.</jats:italic> found that marginal ecosystems—semiarid savannas and low-latitude shrublands—are responsible for most of the variability. Biological productivity in these semiarid regions is water-limited and strongly associated with variations in precipitation, unlike wetter tropical areas. Understanding carbon uptake by these marginal lands may help to improve predictions of variations in the global carbon cycle. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6237" page="895" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aaa1668">895</jats:related-article> </jats:p>

<jats:title>Increasingly rapid ice sheet melting</jats:title> <jats:p> Glaciers on the Southern Antarctic Peninsula have begun losing mass at a rapid and accelerating rate. Wouters <jats:italic>et al.</jats:italic> documented the dramatic thinning of the land-based ice, which began in 2009, using satellite altimetry and gravity observations. The melting and weakening of ice shelves reduce their buttressing effect, allowing the glaciers to flow more quickly to the sea. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6237" page="899" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aaa5727">899</jats:related-article> </jats:p>

<jats:title>Helping the poor invest in sanitation</jats:title> <jats:p> Almost a third of the world's people do not have access to hygienic latrines. Improving access to and increasing the use of latrines would reduce deaths and poor health caused by diarrheal disease. Guiteras <jats:italic>et al.</jats:italic> tested the relative benefits of supplying health information, offering a financial subsidy to purchasers of hygienic latrines, or increasing the availability of latrines for purchase. Providing the subsidy worked best: Nonsubsidized households were more likely to purchase latrines when other households in their village were subsidized. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6237" page="903" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aaa0491">903</jats:related-article> </jats:p>

<jats:title>Brain imagination to control external devices</jats:title> <jats:p> Studies in monkeys have implicated the brain's posterior parietal cortex in high-level coding of planned and imagined actions. Aflalo <jats:italic>et al.</jats:italic> implanted two microelectrode arrays in the posterior parietal cortex of a tetraplegic patient (see the Perspective by Pruszynski and Diedrichsen). They asked the patient to imagine various types of limb or eye movements. As predicted, motor imagery involved the same types of neural population activity involved in actual movements, which could potentially be exploited in prosthetic limb control. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6237" page="906" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aaa5417">906</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6237" page="860" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aab3464">860</jats:related-article> </jats:p>

<jats:title>Chromatin state and the single cell</jats:title> <jats:p> Identifying the chromatin state of any single cell, which may or may not have a different function or represent different stages relative to others collected within any single culture, experiment, or tissue, has been challenging. Cusanovitch <jats:italic>et al.</jats:italic> skirted previously identified technological limitations to identify regions of accessible chromatin at single-cell resolution. Combinatorial cellular indexing, a strategy for multiplex barcoding of thousands of single cells per experiment, was successfully used to investigate the genome-wide chromatin accessibility landscape in each of over 15,000 single cells. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6237" page="910" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aab1601">910</jats:related-article> </jats:p>

<jats:title>A viral DNA form that survives extremes</jats:title> <jats:p> The prokaryote <jats:italic>Sulfolobus islandicus</jats:italic> lives at extreme temperatures (∼80°C) and acidity (pH 3). It is infected by the rudivirus SIRV2. DiMaio <jats:italic>et al.</jats:italic> determined the structure of the SIRV2 virus using cryo–electron microscopy to understand how the virus survives these brutal conditions. Most DNA in nature assumes a B-form shape. The virion, on the other hand, contains highly unusual A-form DNA that may help it survive adverse conditions. The viral capsid protein forms an extended α-helical structure that wraps around the viral DNA, possibly stabilizing the A-form DNA. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6237" page="914" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aaa4181">914</jats:related-article> </jats:p>

<jats:title>Structural signals that direct HIV packaging</jats:title> <jats:p> During the viral replication cycle of HIV, unspliced dimeric RNA genomes are efficiently packaged into new virions at the host cell membrane. Packaging is directed by a region at the start of the genome, the 5′ leader. The architecture of the 5′ leader remains controversial. Keane <jats:italic>et al.</jats:italic> developed nuclear magnetic resonance methods to determine the structure of a 155-nucleotide-long region of the 5′ leader that can direct viral packaging. The structure shows how the 5′ leader binds to the HIV protein that directs packaging, how unspliced dimeric genomes are selected for packaging, and how translation is suppressed when the genome dimerizes. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6237" page="917" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aaa9266">917</jats:related-article> </jats:p>